Harry Wadsworth Holcolm Stillwell was born January 28, 1882, in New Jersey and died December 22, 1951. He was a locksmith, a dealer in model plane kits and a dealer in minerals in Rockville Centre, New York. The family hobby was rockhounding, and he infected his brothers, sisters and nephews with the fever as well. He was particularly fond of fluorescent minerals, and had a substantial collection of them. His obituary in Rocks & Minerals reads as follows:

X "Harry Stillwell, mineral collector and dealer for 60 years, passed away at his home in Rockville Center, Long Island, N.Y., on December 22, 1951. He became interested in minerals when a boy of nine [in 1891] through the curator of the museum at Rutgers University in New Brunswick, N.J., his boyhood home. X "A machinist by trade, he ran a general repair and locksmith shop for the past 24 years and in connection with it sold minerals through his Eastern Mineral & Curio Shop. He had a fine private collection of minerals which his wife is selling to nearby interested mineral collectors. Mr. Stillwell collected extensively over the eastern part of the United States and exchanged on a world-wide basis. He had planned to retire and had sold his business last September. His minerals and most other furnishings were packed and ready to be sent to Putney, Vermont, where he planned to live on his son's farm and run a mineral and gift shop on Route 5. X "Mr. Stillwell belonged to the Old Timers Club, and, at various times, belonged to other mineral groups. He was a member of the Queens Mineral Society. For approximately seven years, before World War II, he and mineral collectors around Rockville Center ran the Long Island Mineral Club, of which Mr. Stillwell had been a founder. X "His wife and sons helped him in his collecting and enjoyed the great pleasure which he got from collecting. He gave away a great deal to young collectors and got many mineral lovers started on their hobby. Nearby schools were helped by being given good collections from his extensive exchange collection. His very friendly and generous spirit and enthusiastic and captivating personality won many mineral lovers to him as their friends. Hw was also the official examiner for the Rocks and Minerals Merit Badge for scout troops for miles around."

Stillwell placed a classified ad in the March 1928 issue of Rocks & Minerals, which read: "Minerals, crystallized and massive specimens; claystones, sand geodes--large variety to exchange for showy or polished specimens. Send list and receive mine. H.W.H. Stillwell, Bellmore, N.Y." He next advertised in 1933-1934, under the business name of "Eastern Mineral & Curio Shop." After that time he did not advertise again until May 1945, when he offered Herkimer diamonds for sale as "H. Stillwell & Son, Rockville Center, N.Y." Shortly thereafter he began to list himself sometimes as "H.W.H. Stillwell," and other times through the end of 1948 as "H. Stillwell & Son."